With the increased use of air conditioners in automobiles, it has been found that system failures may occur because of the circulation of moisture in the refrigerant that adversely affects all components of the system but is especially damaging to the close tolerance components of the compressor. As a result increased repair costs and maintenance may be required.
Such air conditioning compressors are designed to operate on gaseous refrigerant only and include an accumulator that receives liquid and gaseous refrigerant from the evaporator and separates the liquid and gaseous refrigerant allowing only the gaseous refrigerant to enter the compressor. One way that has been used to remove moisture is to provide desiccant in cloth bags in the liquid refrigerant in the accumulator to adsorb moisture from the liquid. Although such a method is simple and inexpensive, it does not efficiently remove moisture since the desiccant adsorbs much less moisture from liquid than the vaporized refrigerant and there is no assurance that the gaseous refrigerant entering the compressor has come into contact with the desiccant.
In U.S. Pat. No. 4,331,001, it has been proposed to hold the desiccant above the liquid level in the accumulator housing and expose all of the vapors entering the compressor to the desiccant to remove any moisture. Although such a system is effective in removing moisture, it involves many parts requiring difficult assembly.
Accordingly, among the objectives of the present invention are to provide an accumulator-dehydrator assembly which is effective to remove the moisture, utilizes a minimum number of parts, is easy to assemble, utilizes low cost materials, and is easy to fill with dessicant.
In accordance with the invention, the accumulator-dehydrator assembly for an air conditioning system comprises an accumulator housing defining an enclosed chamber including an inlet and an outlet in the upper end and a refrigerant and oil accumulator in the lower end and a vapor drier canister assembly comprising a one-piece plastic body defining a closed top wall, a closed side wall and an open bottom. The canister includes an integral outlet projecting into and sealingly engaging the outlet of the housing.
A vapor filter is associated with the outlet of the canister such that refrigerant flows through the filter before passing through the outlet. A perforated plate with a felt pad is provided in the bottom of the canister for holding desiccant within said canister. A refrigerant and oil tube is mounted externally of the canister and has a lower end extending to the bottom of the chamber of the accumulator housing and has an upper end extending into the outlet of the canister. A plastic filter is associated with the lower end of the tube. Spring means yieldingly urges the perforated bottom plate upwardly. The canister has a desiccant filling opening in the side wall thereof, and interengaging means between the bottom plate and the canister for holding said bottom plate in a position such that desiccant can be introduced into the canister after which the bottom plate is released to hold the desiccant in the canister.